Integrated structures with conductive regions having at least one element from group 2 of the periodic table

ABSTRACT

Some embodiments include an integrated structure having a conductive region which contains one or more elements from Group 2 of the periodic table. Some embodiments include an integrated structure which has a conductive region over and directly against a base material. The conductive region includes one or more elements from Group 2 of the periodic table, and has a pair of opposing sidewalls along a cross-section. A capping material is over and directly against the conductive region. Protective material is along and directly against the sidewalls of the protective region.

TECHNICAL FIELD

Integrated structures with conductive regions having at least oneelement from group 2 of the periodic table.

BACKGROUND

Conductive materials have numerous uses in integrated circuitry. Forinstance, the conductive materials may be incorporated into wiring,shielding, wordlines, digit lines, interconnects, etc. A continuing goalof integrated circuit fabrication is to increase integration density. Arelated goal is to decrease the dimension of conductive components,while maintaining suitable conductivity along the components. It wouldbe desirable to develop new materials which are suitable for beingutilized in conductive components, and which may have desired highconductivity (i.e., low resistivity) and acceptable melting temperature.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-6 are diagrammatic cross-sectional views of a portion of anexample construction at example process stages of an example method forfabricating example integrated structures.

FIG. 7 is a diagrammatic cross-sectional view of a portion of theexample construction of FIG. 2 is shown at an example process stagefollowing that of FIG. 2, and alternative to the process stage of FIG.6.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Some embodiments include methods of incorporating one or more elementsfrom Group 2 of the periodic table (e.g., one or more of beryllium,magnesium, calcium, strontium and barium) into conductive regions ofintegrated structures. Example embodiments are described with referenceto FIGS. 1-7.

Referring to FIG. 1, a construction 10 includes a base material 14 overa supporting material 16.

The base material 14 may comprise any suitable composition(s); and insome embodiments may include one or more of nitrogen, carbon andsilicon. For instance, in some embodiments the base material maycomprise, consist essentially of, or consist of one or more of titaniumnitride, silicon nitride, silicon carbide, TiSiN, SiCN, etc., where thechemical formulas indicate primary constituents rather than specificstoichiometries. In some embodiments, the base material 14 may beelectrically conductive (e.g., may comprise, consist essentially of, orconsist of titanium nitride), and in other embodiments the base material14 may be electrically insulative (e.g., may comprise, consistessentially of, or consist of silicon nitride).

The base material 14 has an upper surface 15.

In some embodiments, the base material 14 may have a thickness T1 withina range of from about 10 angstroms (Å) to about 2000 Å.

The supporting material 16 may comprise semiconductor material (e.g.,monocrystalline silicon), and may be referred to as a semiconductorsubstrate. The term “semiconductor substrate” means any constructioncomprising semiconductive material, including, but not limited to, bulksemiconductive materials such as a semiconductive wafer (either alone orin assemblies comprising other materials), and semiconductive materiallayers (either alone or in assemblies comprising other materials). Theterm “substrate” refers to any supporting structure, including, but notlimited to, the semiconductor substrates described above. In someapplications, the supporting material 16 may correspond to asemiconductor substrate containing one or more materials associated withintegrated circuit fabrication. Such materials may include, for example,one or more of refractory metal materials, barrier materials, diffusionmaterials, insulator materials, etc. For instance, if the base material14 comprises conductive material, the supporting material 16 maycomprise an insulative material (e.g., silicon dioxide, aluminum oxide,silicon nitride, etc.) over a semiconductor material.

Referring to FIG. 2, conductive material 18 is formed over the basematerial 14. The conductive material 18 may comprise, consistessentially of, or consist of one or more elements from Group 2 of theperiodic table. In some embodiments, the conductive material 18 maycomprise, consist essentially of, or consist of one or more ofberyllium, magnesium and strontium. In some embodiments, the conductivematerial 18 may comprise, consist essentially of, or consist ofberyllium.

The conductive material 18 may be considered to be configured as aconductive region 19 which is directly against the upper surface 15 ofthe base material 14. In some embodiments, the base material 14 may beselected to be suitable for adhesion of the conductive region 19thereto; and accordingly, the base material 14 may be referred to as anadhesion material. For instance, in some embodiments it is found thatelements from Group 2 of the periodic table (e.g., magnesium, beryllium,strontium, etc.) of conductive region 19 adhere well to an adhesionmaterial 14 which comprises one or more nitrides (e.g., titaniumnitride, silicon nitride, etc.).

In some embodiments, the conductive region 19 may have a thickness T2within a range of from about 50 Å to about 10,000 Å.

An advantage of utilizing a conductive region which comprises one ormore materials from Group 2 of the periodic table is that such may havedesired high conductivity suitable for utilization in highly-integratedconductive structures; and such may also have a melting point suitablefor integrated circuit fabrication (e.g., may have a melting point highenough to enable the conductive region 19 to be formed at the so-calledfront-end-of-the-line during integrated circuit fabrication).

Tungsten is commonly utilized as a conductive material in conventionalintegrated structures. If the conductive region 19 comprises, consistsessentially of, or consists of beryllium, instead of tungsten, such mayoffer a conductivity enhancement of at least about 40% relative to thetungsten.

The conductive region 19 may be formed utilizing any suitableprocessing. For instance, in some embodiments the conductive region 19may be formed utilizing physical vapor deposition (e.g., DC magnetronsputtering). In some embodiments, the conductive region 19 may be formedin situ relative to the base material 14 (i.e., the base material 14 isformed, and then the conductive region 19 is formed over such basematerial without ever exposing the base material to air). In otherembodiments, the base material 14 may be exposed to air prior to beingplaced in a physical vapor deposition (PVD) chamber (or other suitablechamber) where the conductive region 19 is deposited onto the basematerial 14.

The conductive material 18 has an upper surface 21.

Referring to FIG. 3, a capping material 20 is formed over the conductivematerial 18, and directly against the upper surface 21 of the conductivematerial. The capping material 20 may comprise any suitablecomposition(s); and in some embodiments may comprise one or more ofnitrogen, oxygen, carbon and silicon. The capping material 20 may beelectrically conductive in some embodiments, and may be electricallyinsulative in other embodiments.

In some embodiments, the capping material 20 may comprise an oxidizedsurface of the conductive material 18. For instance, in some embodimentsit may be found that oxidation of an exposed surface of the conductivematerial 18 is self-limiting, and accordingly the capping material 20may be formed by exposing the upper surface 21 of conductive material 18to appropriate oxidative conditions (e.g., exposure to air, ozone,etc.). In such embodiments, the capping material 20 may comprise,consist essentially of, or consist of an oxide which includes one ormore elements from Group 2 of the periodic table. For instance, thecapping material 20 may comprise, consist essentially of, or consist ofone or more of beryllium oxide, strontium oxide and magnesium oxide.

In some embodiments, the capping material 20 may comprise a compositiondeposited over the upper surface 21 of the conductive material 18. Suchcomposition may, for example, comprise, consist essentially of, orconsist of one or more of silicon carbide, silicon nitride, SiCN, SiON,etc. (where the chemical formulas indicate primary components, ratherthan indicating specific stoichiometries). The capping material 20 maybe deposited in situ relative to the conductive material 18, and suchmay be preferred if the conductive material 18 is problematicallyaffected by oxidation. The capping material may be formed with anysuitable process, including, for example, a PVD process, a chemicalvapor deposition (CVD) process, an atomic layer deposition (ALD)process, etc.

In some embodiments, the capping material 20 may comprise an oxidizedsurface of the conductive material 18, and may comprise anothercomposition (e.g., one or more of silicon carbide, silicon nitride,SiCN, SiON, etc.) deposited over such oxidized surface.

The capping material 20 has a thickness T3 which may be within a rangeof from about 50 Å to about 200 Å.

The materials 14, 18 and 20 together form a stack 22.

In some embodiments, the stack 22 may be thermally treated with atemperature of less than or equal to about 60% of the meltingtemperature of the conductive material 18 to thermally anneal suchconductive material and enhance conductivity of the conductive material.Such thermal treatment may be additionally, or alternately, utilized forthermally conditioning other materials and compositions associated withthe semiconductor substrate 16 (e.g., for annealing doped regions whichmay be associated with electrical components (not shown) which areincorporated into the semiconductor substrate 16).

Referring to FIG. 4, the stack 22 is patterned into a plurality ofspaced-apart features 24. Such features may correspond to any suitableintegrated structures. For instance, the conductive regions 19 of thefeatures 24 may be incorporated into wiring, shielding, wordlines and/ordigit lines which extend in and out of the page relative to thecross-section of FIG. 4.

The stack 22 may be patterned with any suitable processing. Forinstance, a patterned mask (not shown) may be provided over the stack22, and a pattern may be transferred from such mask through thematerials 20, 18 and 14 utilizing one or more suitable etches.

The conductive regions 19 of the features 24 have exposed sidewallsurfaces 25.

Referring to FIG. 5, protective material 30 is formed over and betweenthe features 24, with the protective material 30 being along anddirectly against the sidewalk 25 of the conductive features 19.

The protective material 30 may comprise any suitable composition(s). Insome embodiments, the protective material 30 may comprise a samecomposition as the capping material 20, and in some embodiments theprotective material 30 may comprise a different composition relative tothe capping 20. Regardless, in some example embodiments the protectivematerial 30 may comprise one or more of the compositions described aboverelative to the capping material 20. For instance, the protectivematerial 30 may comprise silicon nitride, silicon oxynitride, anoxidized surface of material 18, etc.

In some embodiments, the protective material 30 may be formed in situafter patterning the features 24 and prior to exposure of the sidewalls25 to air or other oxidant. In some embodiments, at least portions ofthe protective material 30 may be formed by oxidizing regions of thesidewalls 25.

Referring to FIG. 6, the protective material 30 may be subjected toanisotropic etching to form sidewall spacers 32. The processing of FIG.6 may be optional in embodiments in which the protective material 30 isinsulative.

In some embodiments, the capping material 20 and protective material 30of the construction 10 of FIG. 6 may comprise a same composition as oneanother; and may, for example, comprise, consist essentially of, orconsist of silicon nitride. The base material 14 may comprise the samecomposition as materials 20 and 30 (for instance may comprise siliconnitride), or may comprise a different material relative to the materials20 and 30. For instance, in some embodiments the base material 14 maycomprise a conductive material (for instance, titanium nitride), whilethe materials 20 and 30 comprise insulative material (for instance,silicon nitride).

As indicated above, in some embodiments at least a portion of theprotective material 30 may be formed by oxidation of the conductivematerial 18 along the sidewall surfaces 25. FIG. 7 shows construction 10at an example process stage which may occur after oxidation of thesidewall surfaces 25 to form the conductive material 30. Theconstruction of FIG. 7 also has upper surfaces 21 of the conductiveregions 19 oxidized to form the capping material 20, and in the shownembodiment the capping material 20 and protective material 30 comprise asame composition as one another and merge together to form a shell (insome embodiments an insulative shell) surrounding the top surfaces 21and sidewall surfaces 25 of the conductive regions 19.

In some embodiments, the conductive material 18 of conductive regions 19may include beryllium; and the materials 20 and 30 may comprise, consistessentially of, or consist of beryllium oxide.

The assemblies and structures discussed above may be utilized withinintegrated circuits (with the term “integrated circuit” meaning anelectronic circuit supported by a semiconductor substrate); and may beincorporated into electronic systems. Such electronic systems may beused in, for example, memory modules, device drivers, power modules,communication modems, processor modules, and application-specificmodules, and may include multilayer, multichip modules. The electronicsystems may be any of a broad range of systems, such as, for example,cameras, wireless devices, displays, chip sets, set top boxes, games,lighting, vehicles, clocks, televisions, cell phones, personalcomputers, automobiles, industrial control systems, aircraft, etc.

Unless specified otherwise, the various materials, substances,compositions, etc. described herein may be formed with any suitablemethodologies, either now known or yet to be developed, including, forexample, atomic layer deposition (ALD), chemical vapor deposition (CVD),physical vapor deposition (PVD), etc.

The terms “dielectric” and “insulative” may be utilized to describematerials having insulative electrical properties. The terms areconsidered synonymous in this disclosure. The utilization of the term“dielectric” in some instances, and the term “insulative” (or“electrically insulative”) in other instances, may be to providelanguage variation within this disclosure to simplify antecedent basiswithin the claims that follow, and is not utilized to indicate anysignificant chemical or electrical differences.

The particular orientation of the various embodiments in the drawings isfor illustrative purposes only, and the embodiments may be rotatedrelative to the shown orientations in some applications. Thedescriptions provided herein, and the claims that follow, pertain to anystructures that have the described relationships between variousfeatures, regardless of whether the structures are in the particularorientation of the drawings, or are rotated relative to suchorientation.

The cross-sectional views of the accompanying illustrations only showfeatures within the planes of the cross-sections, and do not showmaterials behind the planes of the cross-sections, unless indicatedotherwise, in order to simplify the drawings.

When a structure is referred to above as being “on”, “adjacent” or“against” another structure, it can be directly on the other structureor intervening structures may also be present. In contrast, when astructure is referred to as being “directly on”, “directly adjacent” or“directly against” another structure, there are no interveningstructures present.

Some embodiments include an integrated structure having a conductiveregion which includes one or more elements from Group 2 of the periodictable.

Some embodiments include an integrated structure having a stack whichincludes a conductive region over and directly against a base material,and which includes a capping material over and directly against theconductive region. The conductive region includes one or more elementsfrom Group 2 of the periodic table. The base material includes one ormore of nitrogen, carbon and silicon. The capping material includes oneor more of nitrogen, oxygen, carbon and silicon.

Some embodiments include an integrated structure which has a conductiveregion over and directly against a base material. The conductive regionincludes one or more elements from Group 2 of the periodic table, andhas a pair of opposing sidewalls along a cross-section. A cappingmaterial is over and directly against the conductive region. Protectivematerial is along and directly against the sidewalls of the protectiveregion.

In compliance with the statute, the subject matter disclosed herein hasbeen described in language more or less specific as to structural andmethodical features. It is to be understood, however, that the claimsare not limited to the specific features shown and described, since themeans herein disclosed comprise example embodiments. The claims are thusto be afforded full scope as literally worded, and to be appropriatelyinterpreted in accordance with the doctrine of equivalents.

We claim:
 1. An integrated structure comprising a conductive regionwhich includes one or more elements from Group 2 of the periodic table;wherein the conductive region is over and directly against an adhesionmaterial comprising one or more of nitrogen, carbon and silicon; andwherein the adhesion material consists essentially of silicon nitride,wherein an upper surface of the conductive region is directly against acapping material comprising one or more of nitrogen, oxygen, carbon andsilicon.
 2. The integrated structure of claim 1 wherein the cappingmaterial is conductive.
 3. The integrated structure of claim 1 whereinthe capping material is insulative.
 4. The integrated structure of claim1 wherein the capping material includes an oxide of at least one of saidone or more elements from Group 2 of the periodic table.
 5. Theintegrated structure of claim 4 wherein the capping material includes atleast one of beryllium oxide, strontium oxide and magnesium oxide. 6.The integrated structure of claim 4 wherein the capping materialincludes beryllium oxide.
 7. An integrated structure comprising a stackwhich includes a conductive region having a bottom surface, an entiretyof the bottom surface being over and directly against an insulative basematerial, and which includes a capping material over and directlyagainst the conductive region; the conductive region including one ormore elements from Group 2 of the periodic table; the base materialcomprising one or more of nitrogen, carbon and silicon; and the cappingmaterial comprising oxygen and the one or more elements from Group 2 ofthe periodic table, and wherein the base material is insulative.
 8. Theintegrated structure of claim 7 wherein said one or more elements fromGroup 2 of the periodic table include one or more of beryllium,magnesium and strontium.
 9. The integrated structure of claim 7 whereinthe conductive region consists of beryllium.
 10. The integratedstructure of claim 7 wherein the base material consists essentially ofsilicon nitride.
 11. The integrated structure of claim 7 wherein thecapping material is conductive.
 12. An integrated structure comprising astack which includes a conductive region having a bottom surface, anentirety of the bottom surface being over and directly against aninsulative base material, and which includes a capping material over anddirectly against the conductive region; the conductive region consistingof one or more elements from Group 2 of the periodic table; the basematerial comprising one or more of nitrogen, carbon and silicon; and thecapping material comprising the one or more elements from Group 2 of theperiodic table and oxygen; and wherein the capping material isinsulative.
 13. An integrated structure comprising a stack whichincludes a conductive region over and directly against a base material,and which includes a capping material over and directly against theconductive region; the conductive region including one or more elementsfrom Group 2 of the periodic table; the base material comprising one ormore of nitrogen, carbon and silicon; and the capping materialcomprising one or more of nitrogen, oxygen, carbon and silicon; andwherein the capping material includes at least one of beryllium oxide,strontium oxide and magnesium oxide.
 14. The integrated structure ofclaim 13 wherein the capping material includes beryllium oxide.
 15. Anintegrated structure comprising: a base material; a conductive regionover and directly against the base material; the conductive regionincluding one or more elements from Group 2 of the periodic table; theconductive region having a pair of opposing sidewalls along across-section; a capping material over and directly against theconductive region; a protective material along and directly against thesidewalls of the conductive region; and wherein the protective materialis a same composition as the capping material.
 16. An integratedstructure comprising: a base material; a conductive region over anddirectly against the base material; the conductive region including oneor more elements from Group 2 of the periodic table; the conductiveregion having a pair of opposing sidewalls along a cross-section; acapping material over and directly against the conductive region; aprotective material along and directly against the sidewalls of theconductive region; and wherein the conductive region includes beryllium,and wherein the protective material comprises beryllium oxide.
 17. Theintegrated structure of claim 16 wherein the capping material alsocomprises beryllium oxide.
 18. An integrated structure comprising: abase material; a conductive region over and directly against the basematerial; the conductive region including one or more elements fromGroup 2 of the periodic table; the conductive region having a pair ofopposing sidewalls along a cross-section; a capping material over anddirectly against the conductive region; a protective material along anddirectly against the sidewalls of the conductive region; and wherein thebase material is conductive; and wherein the capping material and theprotective material are insulative.
 19. An integrated structurecomprising: a base material; a conductive region over and directlyagainst the base material; the conductive region including one or moreelements from Group 2 of the periodic table; the conductive regionhaving a pair of opposing sidewalls along a cross-section; a cappingmaterial over and directly against the conductive region; a protectivematerial along and directly against the sidewalls of the conductiveregion; and wherein the base material, the capping material and theprotective material are all insulative.
 20. The integrated structure ofclaim 19 wherein the base material, the capping material and theprotective material are all a same composition as one another.
 21. Theintegrated structure of claim 20 wherein the base material, the cappingmaterial and the protective material all comprise silicon nitride. 22.An integrated structure comprising: a base material; a conductive regionover and directly against the base material; the conductive regionincluding one or more elements from Group 2 of the periodic table; theconductive region having a pair of opposing sidewalls along across-section; a capping material over and directly against theconductive region; a protective material along and directly against thesidewalls of the conductive region; and wherein the base materialcomprises titanium nitride; and wherein the capping material and theprotective material both comprise silicon nitride.